Flexible welt shoe construction



W. C. WRIGHT FLEXIBLE WELT SHOE CONSTRUCTION March 13, 1945.

Filed Sept. 5, 1941 I 2 Sheets-Sheet 2 I Patented 13, 1945 FLEXIBLE WELT SHOE CONSTRUCTION Wallace 0. Wright, Brookfleld, N. H., assignor to Wright-Batchelder Corporation, Boston, Mass, a corporation of Massachusetts Application September 5, 1941, Serial No. 409,597

1 Claim. (Cl. 36-17) My present invention is'a novel and improved welt shoe whereby the entire shoe structure will be both initially and permanently flexible.

Heretofore, in the manufacture of boots and shoes, particularly welt boots and shoes, it has long been attempted to provide a construction which will insure more flexibility and pliability to' the shoe, particularly to the sole and insole, to eliminate the stiffness, breaking in, and other undesirable features. But all such prior efforts, as far as I am advised, have been unsatisfactory, objectionable, and failed in their effort to give as flexible a shoe construction as was required.

Various efforts toward this end have been made, such as slashing or cutting the insole, cutting out and removing parts of the insole after the outsole was stitched and the shoe otherwise com- *pleted, softening and treating the materials of the shoe by chemicals and the like. The slashing and cutting of the insole was objectionable because of the expense involved, and the weakening of the entire shoe structure; and any use of chemicals which permanently rendered the leather of the .sole and outsole pliable was apt to damage the fibre and rot or otherwise injure the fibre.

It will be appreciated that in the construction of footwear wherein an insole and outsole were united that such a combination necessarily tend ed to stiffen the resultant structure. Similarly, where a welt was used, the vertical sewing rib of the insole added further rigidity to the sole structure of the resultant shoe. h

I have discovered that by making a-welt shoe .with a sewing rib of initially and permanently plastic or flexible material thru which rib the insole and outsole, as well as the upper, was attached by the usual welt stitching that I am enabled to eliminate the inherent rigidity and stifiness heretofore necessarily produced by prior shoe manufacturing methods, and I thus provide a shoe structure with the sole and outsole united by standard attaching methods which will be initially and permanently flexible, will not require any breaking in, will not cause any inconvenience or. discomfort from the upstanding sewing rib between the insole and outsole, and which, furthermore, will increase the flexibility and pliability of the entire shoe structure.

I carry out my invention by utilizing a suitably inherently plastic material forthe sewing rib, which material ,is of suflicient strength to afford stitch-retaining, suiiicient rigidity to facilitate the inseaming operating during the manufacturing processes, and can be readily trimmed with a standard type of inseam trimming machine,.

which removes the surplus upper, lining, and top portion of the sewing rib.

Thus I provide an initially and permanently flexible and pliable shoe structure, without damage or injury to the fibres of the leather, without slashing, cutting out, or removing part of the insole, or the like extra and expensive processes which damage and injure the strength and wearability, and lasting qualities of the shoe.

I find that suitable material for such a pliable sewing rib may be formed from various types of modern synthetic plastics, particularly plasti- Such vinyl resins are referred plastic materials which I flnd suitable' for use as the sewing rib'for my flexible shoe construction is that during the flexing of the shoe during walking and use, such synthetic plastics apparently have a capacity of stretching and compressing without distorting the normal contour of the sewing rib. Thus, during walking the shoe is constantly subject to flexing in the forepart,

and the synthetic vinyl resins I have employed for a sewing rib permit such flexing by alternately stretching and then compressing the rib during such bending or flexing, while-still maintaining the rib in its inherent upstanding normal position and, hence, without putting any undue stress on the stitching nor any restraining action on-the flexing of the outsole and insole despite the fact that such rib is in vertical upstandin position between the outsole and insole.

In prior shoe structures, wherein a leather or composite rib is formed, when the sole is flexed the upstanding rib portion is necessarily distorted by the compression and expansion incident to the flexing action, since such a rib is not sumciently and inherently pliable to allow for the bending of the sole without distorting the vertical upstanding sewing rib, which thereby puts also coninseam stitching. I Thus it will be appreciated that 'a peculiarly difficult problem is presented where a vertical ribis bound between an upper and lower member and yet to provide flexibility throughout the height of the' rib. By my discovery of making such a rib of inherently flexible material, I am enabled to overcome these prior difliculties and thus produce an initially and permanently flexible shoe with an insole and outsoie. Furthermore, my invention provides a rib which will not tend to form ridges or gutters" in the insole, which latter is a highly objectionable feature in the present standard type of welt footwear.

In carrying out my invention, I prefer to prepare or form such a rib with a suitable attaching flange, or flanges, and secure the flange portion to the face of the insole blank by adhesive or other attaching means, or both. Thus, I may attach the flange to the insole by adhesive along the sides and add an occasional Such a rib, while preferably madepf plasticized' vinyl resins,,as above noted may also be formed with reinforcingstrips or layers to give added stitch-retaining where an extremely soft or pliable rib structure is desired, thus permitting a more pliable plastic where reinforcing layers. or stitch-retaining are employed.

Referring to the drawings:

Fig. 1 is aside view of a standard type of welt shoe embodying my invention, with a part broken away; i

Fig. 2 is a fragmentary cross-sectional view of my improved insole with flexible rib;

a slightly modified form;

Fig. 4 is a fragmentary cross-sectional view on' Fig. 11 is a diagrammatic .view. showing the direction in which the Figs. 5 to are taken.

Referring to the drawings, wherein a standard type of welt shoe structure is illustrated incorporating my improved insole and flexible sewing rib, an insole" blank of any suitable: materlal is designated at I, to which my inherently flexible sewing rib 2, with attaching flanges! and l are attached. This sewingriband flange is preferably made of plastic, as above noted, and'is inherently flexible but with suflicient rigidityto constitute a stitch-retaining sewing rib on the insole I.

v Asshown'in Fig. 2, the marginal portion of the insole is recessedslightly, as indicated at I, to receive the thickness o'fthe flanges 3- and i and wives smooth surface on the interior portion Fig. 3 is a similar cross-sectional view showing.

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t of the insole I, the opposite surface I constituting the foot-contacting part.

'In Fig. 3, I show an insole with a sewing rib! and flanges I and l secured directly to .the mars ginal surface of the insole blank I, eliminating the. recessed or cut-away part i.

If desired, the outer portion 4 of the .flange uniting the rib to the insole may be omitted but, preferably, 1 form my flexible sewing rib with 10 face and constituting a, part of the rib structure to secure said rib to the marginal portion of the insole around the forepart and shank by adhesive or other attaching means. With the insole thus prepared,. the same is assembled one last; the

upper materials I2 and It lasted in any suitable and usual manner; the welt I! attached by inseam stitching I8 and, thereupon, the rib 2 or surplus margin of the upper materials are trimmed, filling I! applied, and the outsole 2| fitted and secured by outseam stitching 2| thru the welt It, and the heel 22 applied.

My improved shoe structure as thus completed contains a yielding plastic, initially, and perma- 2 nently flexible sewing rib 2 between the insole and outsole, which rib will yield at all times during walking and flexing of the shoe 'sole. The inherent yield and elasticity of such a plastic sewing rib insures comfort and ease to the foot of the wearer during use, eliminates the formation of ridges on the insole, particularly when the filling II packs down' or "works during use, and gives a resultant connecting element between the insole-upper materials, welt and outsole, which is a distinct novelty in this art as far as I am informed.

It will be appreciated that during the flexin and bending of theshoe structure, my plastic rib, which is inherently yielding, will automatio cally permit the bending and yielding of the inno undue strain is put on the inseam stitching; I6 during such flexing or bending and no restraining of the normal flexibility of the insole and outsole occurs. I have illustrated this feature in diagrammatic form in Figs. 5, 6, and 7, these being partly cross-sectional approximately so in the line of the arrows 2525 of Fig. 11 illustrating the insole I, with the upstanding rib 2 in position thereon, the insole I being shown in Figs. 5, 6, and 7 with the full height of the flange I I, on an enlarged scale, when in position on the shoe, .the insole I and attaching flange I being illustrated in cross-section. Thus, when in normal position, as shown in Fig. 5, the inherently flexible rib 2 thru which the inseam stitching I6 is fitted will maintain its vertical position without distortion even when flexed, as shown in Fig. 6, or in the reverse directlon, as shown in Fig. .7.

Figs. 8, 9, and 10 are illustrative in a similar position, viewing the insole rib in the direction of the arrows 25 of Fig. 11, wherein a normal insale 30, having a sewing rib .cut therefrom and including a gemmed reinforcing material SI covering the upstandingrib and with the gemmed duck 32 along the face of the insole, it will be noted, such an insole is bent orflexed in the contour'as. shown in Fig. 9. theupstanding rib 3| necessarily tending to bend over at the point of flexing, as shown at 33, thus putting an extra strain on the inseam stitching and distorting the normal vertical position of the rib II.

laterally extending flanges on each side of the v Conversely. and as shown at Fig. 10, when the gemmed duck rib attached to the insole of this type is bent in the opposite direction. the vertical part of the rib will necessarily wrinkle as shown at 35, the same being somewhat overdrawn; and 5 in this case, also, will put an undue strain upon the inseam stitching, which resists the flexing or bending action of the shoe during use. The usual gemmed duck reinforcing is applied to the rib 16 cut or split from the marginal edge'of the insole 30 and turned up into vertical position, whereby the gemmed duck reinforcing is appliedand secured by adhesive, which still further tends to stiflen the insole.

In my invention, I prefer to eliminate the gemmed duck reinforcing although the same can be applied, if desired.- a

I claim:

Improved Goodyear welt construction of the kind described, comprising an insole, upper mae terials, and a welt, said insole having adhesively secured, along the marginal surface portion of the forepart and toe a separate sewing rib consisting in an upstanding portion and a horizontal attaching flange, said rib being formed of synthetic vinyl resin material, the upper, insole,' and welt being united by fastenings thru said syn- 10 thetic vinyl resin material, the upstanding 'Portion of said rib material being inherently comressible while maintaining its upstanding position'to prevent guttering of the shoe insole where the upstanding portion is secured to said insole,

15 and said material being sufllciently plastic to absorb breaking strains on'the fastenings during the flexing of the shoe.

' WALLACE C. WRIGHT, 

